This archive report was first published on 23 October 2019.
Wildfires: A Complex Mix of Human and Climate Factors ¶
As wildfires continue to ravage California, a question on everyone's mind is: what's causing these devastating fires? The answer, according to Adam Sobel, an atmospheric scientist and director of the Initiative on Extreme Weather and Climate at Columbia University, is a complex mix of human and climate factors.
On one hand, human actions such as poorly maintained electric power lines and uncontrolled carbon emissions are contributing to the problem. PG&E, the utility company responsible for maintaining the power grid in California, has been criticized for its handling of the situation. Sobel notes that if PG&E's wires provide the spark that ignites a fire, then the company is responsible.
On the other hand, climate change is also playing a significant role in the increasing risk of wildfires. Heat dries out vegetation, making it more susceptible to burning. Tree rings show that there have been droughts even worse than those in the past century, and fire has been a part of the natural history of California and the western United States for millennia. However, human greenhouse gas emissions are making the problem worse by increasing the risk of wildfires.
The situation is not unique to wildfires. It's a generic problem that applies to a wide range of increasing climate risks. Disasters happen when a geophysical hazard meets people. Floods, for example, occur not just because of storm surges or heavy rains, but also because of unwise development in flood plains or failures of infrastructure.
The important distinctions are ethical as much as they are scientific. Natural climate variability is out of human control. Building homes in dangerous places isn't. Neither are poorly maintained electric power lines or continued uncontrolled carbon emissions.
As Sobel notes, the answer to all of these questions is yes. Human actions and climate change are both contributing to the problem of wildfires in California.
